Heretofore, the disposal of wet refuse by municipal corporations and others has commonly been carried out by either incineration or burial-in-soil system. While some municipal corporations rely on natural decomposition by installing top-lidded and bottom open buckets on the soil and charging domestic wet refuse or garbage into the buckets, there is no apparatus for disposal at present whereby wet refuse may be decomposed and consumed as such in its original form while saving of space and energy as well as reducing of the time required for disposal can be accomplished.
It is the incineration system that has been most utilized in the prior art. However, it not only requires enormous initial costs for incineration facilities, combustion gas cleaning facilities, odor removing facilities, and the like as well as high fuel costs, but also has been one of sources of carbon dioxide emission which is in turn a cause of the global "warming-up" phenomenon, the solution of which is hastened from the aspect of preservation of regional as well as global environments.
With regard to the burial-in-soil system, the area in which refuse may be dumped to reclaim land is limited in such narrow land situations as in our country. Further, this country should also be careful about the filling-in of the foreshore as one of countries which have ratified the International Treaty for Prevention of Ocean Pollution, since filling-in of the foreshore constitutes one of causes of ocean contamination. It cannot but be said that the burial-in-soil system is a quite unreasonable means especially with respect to the environmental aspect. In addition, the use of wet refuse to reclaim a land would be a source of evil odor and harmful insects, so that since the burial-in-soil system can be accomplished only in remote areas away from residential districts, it is very infeasible from an economic aspect as well, because of the vast transportation and labor costs involved as well as requirements of spacious sites for dumping refuse and then covering the refuse with soil.
The system in which wet refuse is dumped into top lidded and bottom open buckets installed on the soil has the following problems when wet refuse as produced in households is dumped into such buckets everyday:
1. It is involved with very offensive odors; for even with lidded buckets, it is impossible to confine odor molecules produced less than 1 ppm which are sensible to the human nose.
2. Wet refuse as stored in garbage cans such as plastic vessels, the aforesaid top-lidded, open bottomed buckets and the like can be picked out and scattered about by dogs, cats, rats and other small animals.
3. The rate at which the refuse is rotted and decomposed is very slow. There is virtually no consumption of refuse by natural decomposition with the system in which refuse is merely dumped and allowed to be deposited in plastic vessels. Vegetable rubbish, leavings of meals and other cooked remains as produced everyday are thus accumulated to ultimately fill up garbage vessels. Particularly, cellulosic wet refuse such as vegetable rubbish are allowed to dry and be accumulated in an undecomposable state.
4. It may be no problem to carry wet refuse to the garden or field where garbage cans are placed. But, upon opening the lid of the can to dump it, the previously dumped refuse would emit an offensive smell to give one physical and mental pains.
5. Offensive odor from wet refuse would be one of causes of environmental pollution especially in densely populated districts.
The system in which residents are supposed to take wet refuse to predetermined places on days designated by a municipal corporation for collection of wet refuse have also a number of problems as listed below.
a. The residents in the vicinity of a place designated for collection of wet refuse are much annoyed by the bad odor and appearance of the refuse as well as scattering of the refuse by small animals such as dogs, cats and rats.
b. As collection of wet refuse usually takes place twice a week in most municipal corporations, residents are obliged to store wet refuse for a few days in a household. Especially in summer, odor from the wet refuse can, even if it is sealed in a bag, penetrate and disperse out through the bag to be a cause of pollution of the residential environment.
c. In residence such as ferroconcrete apartment houses and high-rise buildings, when carrying wet refuse to a designated place on a day designated for collection, soiled water oozing out of wet refuse can often drip down on the corridors or elevator floors to be a cause of odious smell and contamination.
d. Depending on the next date and time designated for refuse collection, residents may sometimes be forced to change the cooking plan as by avoiding the menu requiring cooking materials difficult to be preserved such as fresh fish or the like.
e. While there is a system in which whenever wet refuse is produced, it is crushed, put into a bag and taken to the designated place on a designated day for collection, there is no essential difference as with respect to emittance of offensive odor.
f. There is yet another system in which wet refuse is frozen for preservation until a day designated for collection. However, it makes no difference in the labor required for carrying the refuse to a designated place for collection, in addition to involving heavy expenses for electric power for continuous operation of the freezer and other maintenances.
g. The time for refuse collection is usually set at the busy hour in the morning twice a week, making residents feel restless.
h. It is bothersome to take refuse outdoors in severe climatic conditions such as the cold winter time and rainy summer season.
i. While some municipal corporations recommend that the use of vinyl bags for wet refuse be avoided as much as possible and that expensive water-proof paper bags be used, residents can be troubled with being short of such bags through carelessness.